It's not about looks. New York architect Rafael Vinoly is the first one to say so. The truth of his conviction is evident on seeing the colossal new hospital he designed at the University of Chicago that opens Feb. 23 called the Center for Care and Discovery.

To be fair, the center's design was driven by performance and flexibility. It aims to offer present-day medical technology of staggering complexity and up-to-date patient care while providing flexibility for future development.

"This is a case where the back of the house really is more important than the front of the house," Vinoly says.

The original hospital program was for a tower that would have occupied just half the present site. It's easier to make a tall building graceful and beautiful than it is to mold a low building with massive two-block-long floors into something presentable. Butlarger floors can support economy and efficiency, fewer vertical trips means fewer elevators. Valuable floor space is recaptured. Larger floors mean there's more room to position patients and services in ways that support care and collaboration among staff members — two items of great importance to the client.

During the architects' candidate interviews Vinoly told university officials that the program was wrong, that they should build a low building with massive floor plates rather than a tower. The officials, to their credit, agreed even though it meant demolishing a needed parking garage to double the site size. Rafael Vinoly Architects won this $700 million commission in 2005, the firm's second from the university after the Booth School of Business.

So it is that the massive new hospital center spans South Maryland Avenue on 57th Street between Cottage Grove and Drexel avenues. (In exchange for the right to pass over Maryland Avenue, the city requires the university to maintain the street.) The hospital is just 10 stories high — although it looks more like 20 — and encloses 1.2 million square feet, a little more than 100,000 square feet per floor (just less than half the total square footage of the 100-story John Hancock Center). Approaching it on foot is like approaching the Himalayas if the Himalayas had no foothills.

It's intimidating. And, it has to be said, with its bands of alternating dark glass windows and light-colored cladding, the hospital looks like a landlocked cruise liner.

Looking, however, at the building's planning and implementation, there is a lot to praise. The planning principles are smart and surprisingly straightforward given the complexity of what is being housed.

Flexibility — the fundamental transformation of rooms or entire zones — is at the top of the list. It is desirable because of the rapid rate of change in health care. New technology, medical techniques and even standards of care have changed profoundly since the 1970s when the Bernard A. Mitchell Hospital, which the center substantially but not entirely replaces, was built.

Minimally invasive surgery is becoming commonplace and more widely applied to different conditions. That shortens recovery from weeks to days and often moves it out of the hospital to the home. It's known that patients do better if they do not stay in the hospital and if they get up and move around as soon as possible. People who stay in the hospital now are more likely to be dangerously ill or suffering from a combination of problems. There are many more equally drastic developments, each with its own cascading implications for hospitals.

Who knows what the next development will be? Flexibility provides no predictive powers; it just allows accommodation, maybe, for whatever comes.

There's maybe no better example of commitment to flexibility than the two floors in the center that have been left empty. For now, there are no plans as to how they will be used, just a conviction that they will be needed. It's possible that some or all of what remains at Mitchell — labor and delivery, the burn unit and the emergency room — could be transferred to the center. What becomes of those floors could be something entirely new.

Flexibility drove the architects to devise a precise structural module of just less than 32 by 32 feet. Every type of room in the hospital that cannot be interrupted by support columns — like operating rooms and patient rooms — fits inside that module or a subset of it. That means spaces can be adapted to different purposes when the need arises by subdividing or expanding.

The hospital looks taller than a 10-story building from outside because service zones as deep as 9 feet are concealed above dropped ceilings that nearly double the hospital's height and volume. Conventional and specialized systems are run through the cavities and dropped down to specific locations. It's another kind of flexibility. Systems that become outdated can be replaced. What's broken can be repaired. This is not new; hospitals have used the strategy for a long time, and offices employed a variation before wireless came along. It's the exhaustive degree to which that ceiling cavity is being deployed and what it contains that are new.

A new air exchange system, for example, runs throughout the building. In operating rooms and patient rooms, the air turnover is accelerated to prevent the spread of infections.

All of the 240 patient rooms are private because patients prefer it and as a further measure to prevent infections from spreading. Lessons about the health value of psychological well-being have been taken to heart. The rooms are as impressive for the comforts they offer patients as they are for their technology.

The rooms are on the top three floors where the views are best. They are large, providing seating for visitors and a convertible couch when someone wants to stay overnight. Hallway alcoves looking into patient rooms allow nurses to observe without intruding. Communications systems give medical staff real-time data on patients and give patients the power to call nurses directly. Each room is stocked with the same equipment as an intensive care unit. The room converts so the patient does not have to be moved. Other aspects that have made hospital stays miserable — like lighting that wakes a sleeping patient and noisy hallways — have been attended to. That old saw about the nurse waking a patient to administer a sleeping pill? That's over.

There are places in the center that feel as though the future is visiting early. The most astonishing of these are called hybrid procedure rooms. They have robotic arms and sophisticated imaging equipment. Multiple monitors display images from different points inside the patient's body. Cameras and microphones are within reach of everyone in the room. The point of the hybrid rooms is to allow doctors to collaborate on a single patient. Doctors working in the hybrids have to train just to learn how to move around the patient without disrupting others.

These facilities offer incredible capabilities and opportunities. As a teaching hospital directly related to the university's medical school and its research laboratories, the effects of collaborative work can be amplified many times over.

Efficiency influenced planning. Notably, the hospital lobby has been hoisted to the seventh floor from its customary place on the ground level. In the lobby all arrivals are received and checked in at separate points for either in-house stays or out-patient procedures. The lobby is open and enormous with seating areas arranged around it. Small private rooms are on the far opposite ends of the floor where doctors meet with families.

The views of the city and nearby park are lovely and may offer a distraction to relatives during their long waits, but the architects' reason for placing the lobby there was practical. Near the center, the path to most destinations is shorter than it would be from the bottom. Doctors can move in a short circuit, for instance, from surgery on the sixth floor to the lobby on seven to speak with a family and back to six for another surgery.

Planning for the center began six years before the Affordable Care Act passed in 2010. "Now health care is front and center for everybody" says Sharon O'Keefe, president of the new center. With the legislation, patient satisfaction matters, as do treatment outcomes. There are financial consequences for hospitals that do not provide high-quality care that is cost-effective. O'Keefe describes financial tightening with systemized inventory management and distribution as one of several lean management methods being used to control costs at the center. The center started without the law as a catalyst, but on its completion, the center stands equipped to satisfy its requirements, according to O'Keefe.

That brings us back to the matter of how the center looks. The either/or, beauty or function is a false opposition. It is possible to do both without sacrificing either.

As civic institutions, hospitals are engaged with the community in a reciprocal relationship of trust and respect. The way a hospital looks matters. It should express something of the pact it has with the public. A welcoming and dignified aspect is needed. The center — with its entry underneath the building at Maryland Avenue — is dark and foreboding at the front door. We've started off on the wrong foot, and we've only just met.

Approaching it, the building's bulk is only emphasized by horizontal banding. The repetitive, undifferentiated exterior suggests indifference — only one grade higher than contempt — for puny you. There's a strange disconnect between the outside and the inside of the center. So much thought and care have gone into making the interior as comfortable as circumstances permit. None of that is evident outside. While the architects have planned the center well for medical staff and patients, they could have done much more with the countenance the center presents to the city.

Cheryl Kent writes on architecture for the Tribune and other publications. She can be reached at cheryl.a.kent@me.com.